Rotary machines, such as turbochargers and compressors, may be used in an engine system to increase pressure of air supplied to the engine for combustion. A turbocharger generally includes an exhaust-driven turbine disc mechanically coupled to a compressor wheel. Rotating at high speed against a significant head pressure, the compressor wheel is subject to extreme mechanical stress during engine operation. If the compressor wheel is defective, such stress may cause the wheel to fracture. In some scenarios, fracture of the compressor wheel may cause the wheel to burst into fragments, resulting in damage to various parts of the turbocharger and/or the engine. In particular, high-velocity fragments that break through the compressor wheel housing may damage various other engine components, cause injury, etc. The extent of the damage may be limited, however, if the fragments of the burst compressor wheel remain confined within the housing.
In a state-of-the-art diesel locomotive, for example, the turbocharger includes a compressor wheel housing which surrounds a compressor wheel that rotates to increase angular momentum of a gas, and a volute that collects the gas and delivers it to an outlet. The volute is coupled to a bearing housing at a volute assembly-bearing housing joint by a plurality of fasteners. During a compressor wheel burst event, the compressor wheel housing may contain the compressor fragments, however, the high-velocity fragments may impact the volute assembly-bearing housing joint with such a force that volute assembly-bearing housing joint failure occurs.